USE OF SURFACE RESPONSE METHODOLOGY FOR OPTIMIZATION OF BIODIESEL PRODUCTION (GROUNDNUT OIL AS A CASE STUDY)

Abstract

Due to increasing global warming and pollution emanating from vehicle exhaust emissions,the use of biodiesel as alternative fuel for diesel engines has increased. The effects of reaction temperature, catalyst concentration and methanol-oil molar ratio on the transesterification process of groundnut oil to biodiesel were investigated. Optimization of the three process parameters and their quadratic cross effect were carried out using a three level-three factor central composite rotatable design model and response surface methodology with each factor varied over three levels. The biodiesel yields were taken as the response of the designed experiment; the data obtained were mathematically analyzed to get an optimum conditions for optimization of biodiesel yield as a function of the three independent parameters. Out of the twenty (20) runs, the optimization produced nine (9) feasible solutions, whose desirability equals to 1 and the selected (most desirable) condition was found to be; at a steady reaction time of 2 hours and constant stir speed of 450 rpm, the reaction temperature of 65°C, catalyst concentration of 1.0 % wt and methanol to oil molar ratio of 7:1. The optimum yield of biodiesel for this condition was found to be 80.72%. The desired conditions were used for biodiesel production and the experimental yield was close to the predicted value. The biodiesel properties were characterized and the results obtained were found to satisfy the standard for both the ASTM D6751 and EN 14214.